This application is based on Patent Application No. 11-317534 filed Nov. 8, 1999 in Japan, the content of which is incorporated hereinto by reference.
The present invention relates to a card connector for removably holding an IC card such as memory card and more specifically to a card connector having an erroneous insertion prevention function to prevent the IC card from being inserted to a connected position when the IC card is inserted in an inappropriate state, e.g., upside down.
Today the memory capacity is rapidly growing thanks to the remarkable advance of electronic circuit integration technology and there is a growing trend for using thin, small IC cards in the recording of various information such as characters, video and audio. Under this circumstance a variety of connectors for connecting the IC cards and electronic devices are being proposed and implemented.
FIG. 10A and FIG. 10B show one example of currently proposed IC card 1. As shown in the figure, the IC card 1 has a card body 2 incorporating an IC circuit in an almost rectangular case and a plurality of contacts 3 connected to the IC in the card body 2 and lead out from the card body 2 to an external front end of the body 2. The card body 2 is formed with a raised portion 4a protruding outwardly on its back surface 4 and also with a inclined surface 5 at one corner.
The raised portion 4a is rectangular in shape with its width t1 between side surfaces 4a2, 4a2 which is smaller than a width between outer side surfaces 1a, 1a of the card body 2. The raised portion 4a shown here includes a plurality of separation walls 6 formed in the front portion of the back surface 4 of the card body 2 to separate contacts 3 from one another. The contacts 3 are attached on the back surface 4 between the separation walls 6 securely.
The inclined surface 5 is formed by cutting one corner of the front part of the card body 2 at angle, which makes the front part of the card body 2 asymmetric with respect to the direction of card insertion (X direction).
FIG. 11 shows a card connector 10 for holding the IC card. The card connector 10 has a connector body 11 for holding the IC card 1 so that it can be inserted and retracted, and also electric contacts 12 for making electric contact with the IC card 1 inserted into the connector body.
The connector body 11 has side portions 13, a bottom portion 14, and a top plate portion 15. The side portions 13 have first side walls 13a for guiding sides surfaces of the IC card 1. The bottom portion 14 has support surfaces 14a for supporting the back surface 4 or front surface 7 of the IC card 1 and stepped portions 14b that engage the raised portion of the IC card so that the raised portion 4a can be moved in the direction of IC card insertion and retraction. The top plate portion 15 keeps the IC card 1 from floating up. The electric contacts 12 are disposed to correspond to the contacts 3 of the IC card 1 and held on the bottom portion 14 like cantilevered springs.
The connector body 11 is placed at a predetermined position on a printed circuit board of an electronic device, with the lower end portions of the electric contacts 12 soldered to predetermined conductive portions of the printed circuit board.
When the IC card 1 is to be connected to the card connector 10 of the above construction, it is inserted into the insertion direction (X direction) with the front surface 7 facing up, the back surface 4 supported on the support surfaces 14a and both of the outer side surfaces 12, 12 of the IC card 1 guided by both of the side walls 13a of the connector body 11. At this time, the side surfaces 4a2, 4a2 of the raised portion 4a formed on the back surface 4 of the IC card 1 engages the stepped portions 14b of the bottom portion 14 of the connector body 11 as the IC card 1 is inserted.
Then, when the front end portion of the IC card 1 abuts an abutment portion 16 of the connector body 11 (see FIG. 14), the contacts 3 contact the electric contacts 12, thus completing the connection (see FIG. 12). In this insertion operation, the IC card 1 is prevented from floating upward and getting dislocated by the inner surface of the top plate portion, so anyone can perform an insertion and connection operation easily and correctly.
In the connector shown in FIG. 11, as long as the IC card 1 is oriented correctly while being inserted, the connection to the card connector 10 can easily and reliably performed. When the IC card 1 is wrongly oriented and inserted, the card connector may be damaged. This is the problem with the conventional card connector that degrades the operability.
For example, when the IC card 1 is inserted upside down, as shown in FIG. 13, the raised portion 4a formed at the bottom of the IC card 1 and protruding upward abuts against the rear end of the top plate portion 15, as shown in FIG. 14. This state, however, is not a completely inserted state and there is a chance of the user further pushing the card with force.
In this case, because the raised portion 4a projects slightly above the inner surface of the top plate portion 15 as shown in FIG. 14, the IC card 1, when applied with a strong push, is forcibly inserted between the bottom portion 14 and the top plate portion 15 of the connector body 11, as shown in FIG. 15, deforming the top plate portion 15.
In the event of such a trouble, the side portions 13 of the connector body 11 are also deformed along with the top plate portion 15, exerting a load on soldered fittings on the side portion 13 of the connector body 11 used to secure the connector to the printed circuit board and also on soldered portions of the contacts, which in turn causes the soldered portions to come off, degrading the connection reliability of the connector.
The present invention has been accomplished to solve the above-described problems of the card connector and provide a highly reliable card connector capable of preventing the IC card from being inserted in an inappropriate orientation and thereby protecting the card from being damaged due to the inappropriate insertion.
To solve these problems, the present invention has the following construction.
According to an aspect, this invention provides a card connector having a connector body for removably holding an IC card and electric contacts for making electric connection with the IC card inserted into the connector body, wherein the IC card has on its back surface a raised portion and is slightly narrower than a connector body width between its both side surfaces, the connector body comprising: a pair of left and right side portions each having a first side wall, the first side walls guiding left and right side surfaces of the IC card in an insertion/retraction direction of the IC card; a bottom portion having a support surface to support a front surface or back surface of the IC card and a pair of left and right second side walls, the second side walls projecting inwardly from the first side walls and, in an IC card back surface supporting state, guiding side surfaces of the raised portion formed on the back surface of the IC card in the insertion/retraction direction of the IC card; a top plate portion provided opposite the bottom portion to keep the inserted IC card from floating up; and an erroneous insertion prevention mechanism to allow the insertion of the IC card when it is inserted into the connector body in an appropriate state with the front surface of the IC card facing up and, when the IC card is inserted in an inappropriate state with the front surface facing down, to block the forward movement of the IC card in the card insertion direction at a blocking position, the blocking position being set a predetermined distance forward from a rear end of the card body; wherein the erroneous insertion prevention mechanism has: a blocking member retractably supported on one of the first side walls in such a manner that when the blocking member is projected, it is situated inward from the second side wall and that when the blocking member is retracted, it is situated outward from the first side wall; and an urging means to normally urge the blocking member to project inwardly from the second side wall; wherein when the IC card is correctly inserted, the blocking member is guided by the inclined surface 5 formed in the IC card to be retracted outwardly from the first side wall and when the IC card is wrongly inserted, the blocking member abuts against a front end of the IC card, blocking the further insertion of the IC card at the blocking position; wherein the left and right second side walls and the support surface of the bottom portion are eliminated in an area ranging from a rear end of the first side wall to the blocking position.
Rather than eliminating the second side walls and the support surface of the bottom portion in an area ranging from the rear end of the first side wall to the blocking position, it is possible to increase the distance between the top plate portion and the opposing support surface of the bottom portion in the area ranging from the rear end of the first side wall to the blocking position or to form an engagement groove in that area to movably receive the raised portion of the IC card in the card insertion/retraction direction. The engagement groove may be formed by a notched groove formed slightly wider than the raised portion and extending inwardly from the rear end of the top plate portion with respect to the IC card insertion direction, or may be formed by a recessed surface portion recessed upward from the underside of the top plate portion.
Further, in this invention, if the distance from the rear end of the first side wall with respect to the IC card insertion direction to the blocking position is set larger than the length in the IC card insertion direction of the inclined surface of the IC card, the movement of the IC card as it is inserted can be stabilized, enabling the wrongly inserted IC card to be more reliably blocked by the blocking member.
The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.